1. Field of the Invention
The present invention relates to a vehicle navigation apparatus that receives destination information generated outside a vehicle via wireless communications and provides guidance instructions based on the received information.
2. Description of the Related Art
A navigation system for automobiles is known whereby an occupant of a vehicle communicates with an operator at a remote communication center, notifying the operator with a destination so that the operator can search a database for information about the destination and transmit the destination information back to the vehicle. In the vehicle, guidance instructions are provided based on the received destination information (see Japanese Laid-Open Patent Application No. 10-253377, for example).
This system is advantageous compared with another system that provides guidance based solely on map information stored in a vehicle-mounted recording medium because the map information stored outside the vehicle enables the installation of a large-scale database, which in turn makes it possible to provide more precise guidance instructions. In other words, while the vehicle-mounted recording medium is subject to a number of size and cost limitations, a recording medium installed in an external facility suffers from less such limitations. Furthermore, by connecting the external facility to a content provider, for example, it also becomes possible to update the maps, names of locations and buildings, or other information such as coordinates in the external database quickly. As a result, guidance that is based on the most up-to-date information can be provided.
However, because the communication between the vehicle and the external facility requires some time (including the time for the occupant, such as a driver, to convey a destination and the time for the vehicle to receive destination information in the form of an electric signal), a problem arises that the start of guidance is delayed compared with the guidance based solely on the map information stored in a vehicle-mounted recording medium. This problem may actually lead to a situation where the vehicle has moved in a direction opposite to the destination by the time the guidance is provided.